The present invention relates to bottle coating and, more specifically, to a method of coating the exterior surface of a glass bottle with a band of plastic material that extends around the bottle to protect the bottle from scuffing.
Many of the glass bottles which are used for beer and soft drinks are reusable. The purchaser leaves a bottle deposit with the grocery or supermarket and when he returns the emptied bottles, his deposit is refunded. Glass bottles may be cleaned, sterilized, and refilled with a beverage many times. Such extended usage of a bottle accentuates severely the problems encountered with scuff marks on the exterior surface of the bottle. Such scuffing typically occurs as a result of the exterior surface of the bottle, adjacent the larger diameter portions of the bottle, contacting bottle handling and filling equipment, other bottles, and bottle containers. Scuff marks left on surface of the bottle impair markedly the appearance of the bottle and therefore detract from the marketability of the bottled beverage.
One approach taken to eliminate the difficulties previously encountered with unsightly scuffs on returnable bottles is disclosed in U.S. Pat. No. 4,370,385, issued Jan. 25, 1983, to Yoshida, and U.S. Pat. No. 4,273,834, issued June 16, 1981, to Yokokura et al. These two patents relate to a composition which, when applied to the scuffed area on the bottle, makes the scuff marks much less noticeable, thus masking the scuff marks.
Another approach to the problem of abrasions on glass bottles is shown in U.S. Pat. No. 3,950,199, issued Apr. 13, 1976, to Lucas. The Lucas patent suggests substantially completely covering a glass bottle with a coating material to protect the bottle. The upper, shoulder area of the bottle is coated with a film of organic polymeric material. A cylindrical sheath of contractable thermoplastic material is then placed around the main body portion of the bottle and heat-shrunk onto the bottle. The Lucas patent is concerned with the prevention of severe scratches and abrasions which cause a reduction of the strength of a glass bottle. Lucas is not concerned with the cosmetic nature of scuffs but rather focuses on their effect on bottle strength. As a consequence, Lucas finds it necessary to coat bottles substantially completely.
U.S. Pat. No. 3,912,100, issued Oct. 14, 1975, to Graham et al discloses a bottle coating arrangement in which a coating is first formed by applying organic plastic materials over localized exterior surface areas of the bottle so that a sleeve or sleeves of heat-shrinkable thermoplastic material may then conform to the surface of the bottle in a snug fitting relationship. This encapsulation of the bottle increases bottle strength substantially while, at the same time, increasing safety in the event that the bottle breaks. In similar fashion, U.S. Pat. No. 3,542,229, issued Nov. 24, 1970, to Beyerlein discloses applying sheaths of stretchable heat-shrinkable plastic film to a bottle and then shrinking them onto the bottle. Such heat shrink plastic banding is effective, but unsightly, thus reducing the positive effects gained from eliminating scuffs.
Finally, U.S. Pat. No. 4,207,356, issued June 15, 1980, to Waugh discloses apparatus for coating an entire bottle with a plastic liquid material. The liquid is flow coated onto the exterior surface of the bottle as the bottle is rotated. The liquid material is supplied to the bottle surface by means of a plurality of liquid supply tubes. Subsequent to application and smoothing of the liquid material, curing is effected by irradiating the material with infrared radiation.
While the Waugh '356 patent discloses complete bottle coating, it will be appreciated that such coating is relatively expensive due to the quantity of plastic liquid which is consumed. Although complete coating of the surface of a bottle is usually not needed to prevent scuffing, especially where the bottle varies in diameter, prior art techniques have not permitted only coating a portion of the bottle surface and making the transitions between coated and non-coated areas smooth and precise. It is seen, therefore, that there is a need for a simple, economical method of protecting bottles from scuffing by coating in bottles only in the areas where scuffing is most likely to occur.